China’s southern provinces are bracing for Typhoon Matmo, as Guangdong authorities relocated more than 150,000 residents and Hainan has suspended rail services across the island.

The National Meteorological Centre on Sunday said Matmo, the 21st typhoon of the year, had strengthened into a severe typhoon that morning and was expected to bring strong winds and heavy rain to areas across Hainan province, Guangdong province and the Guangxi Zhuang autonomous region.

The storm is expected to move northwestward at a speed of 20 to 25km/h (12 to 15mph), gaining further strength before making landfall along the coast between the cities of Wuchuan in Guangdong and Wenchang in Hainan about midday on Sunday, the centre said. Matmo’s intensity is set to gradually weaken after landfall.

The Chinese weather authority also kept the red typhoon alert – the highest level in its four-tier alert system – which it raised from orange on Saturday evening.

In anticipation of Matmo, a total of 151,352 people were relocated across Guangdong, with more than 10,000 emergency and rescue personnel deployed as of 8pm on Saturday, state broadcaster CCTV reported, citing Guangdong’s emergency management authorities.

At a provincial meeting on Typhoon Matmo preparedness on Saturday, Meng Fanli, Guangdong’s deputy party secretary, called on local authorities and departments to “swiftly go into battle mode” and “carry out typhoon prevention work with the strictest standards, utmost precision and concrete measures”, local media reported.